Conventionally, the following methods have been known for producing a fluorine-containing acrylic acid ester.    (1) A method in which α-(trifluoromethyl)acrylic acid is allowed to react with thionyl chloride to render it α-(trifluoromethyl)acrylyl chloride, which is then reacted with a fluorine-containing alcohol in the presence of a base to generate α-(trifluoromethyl)acrylic acid ester (Patent document 1).    (2) A method in which α-(trifluoromethyl)acrylic acid is allowed to react with a fluorine-containing alcohol or methanol in the presence of fuming sulfuric acid to generate α-(trifluoromethyl)acrylic acid ester (Patent document 2).    (3) A method in which 2-bromo-3,3,3-trifluoropropene is allowed to react with ethanol in the presence of palladium catalyst, carbon monoxide, and triethylamine single base (Patent document 3).
However, the method (1) has such a drawback that the yield of converting reaction into α-(trifluoromethyl)acrylyl chloride is low, and an anhydride is generated as a byproduct. The method (2) has such a drawback that use of a great amount of hard-to-handle fuming sulfuric acid is necessary. The method (3) has such a drawback that alkoxy fluorine-containing propionic acid ester is produced as a main product. In this patent document, we can find the description “1,1,1-trifluoro-2,3-dihalopropane may be used while directly converted into 2-halo-3,3,3-trifluoropropene within the system” but not a practical example for reaction with alcohol. Also, the fact that reaction in the presence of two or more kinds of bases will improve the yield of fluorine-containing acrylic acid ester has never been known (see Comparative examples).
(Patent document 1) Japanese Examined Patent Publication No. Hei 3-8329
(Patent document 2) Japanese Patent Laid-Open Publication No. Sho 60-42352
(Patent document 3) Japanese Patent Laid-Open Publication No. Sho 58-154529